In a known circular knitting machine of this type (DE 19 44 454 A1) the cylinder and dial cams, or respectively the segments which form same, are disposed around an axis of rotation so as to be rotatable relative to one another. This serves the purpose of optionally adjusting the dial cam to synchronous draft or timing and afterdraft or delayed timing, respectively, in order thus to withdraw the dial needles simultaneously with the cylinder needles or—when viewed with respect to the circumferential direction of the needle cylinder—somewhat later than the latter into their completely drawn-back position (couliering position). Moreover the entire dial arrangement is mounted displaceable parallel to the axis of rotation, so that the height of the dial arrangement above the needle cylinder alters and thus the stitch length of the knitted goods to be produced on the circular knitting machine can be adjusted.
A problem with circular knitting machines of this type, which has so far not been satisfactorily solved, consists in the mounting of their thread guide elements, which serve to supply threads to the individual knitting points or systems. If a height adjustment of the dial arrangement takes place, then the height of the thread guide elements or respectively of the entire thread guides should be correspondingly altered so that the eyes or the like on them substantially maintain their relative position relative to the dial needles. If on the other hand the dial cam is rotated relative to the needle cylinder cam, in order for example to move from synchronous timing to delayed timing, then the thread guides should not be also rotated but should substantially maintain their relative position relative to the cylinder cam. This applies irrespective of whether the circular knitting machines have rotatable needle cylinders and dials and stationary cylinder and dial cams, or stationary needle cylinders and dials and rotatable cylinder and dial cams.
In the known circular knitting machine of the type described initially, the thread guides and all their parts are secured for this purpose o a common holding ring which is secured with the aid of carrier rods disposed parallel to the axis of rotation on a carrier which is disposed above the dial arrangement. This carrier can be moved up and down together with the dial arrangement but, during rotary movements of the dial cam relative to the cylinder cam, maintains its position relative to the cylinder cam segments. Thus the desired positions of the thread guides are automatically secured. What is disadvantageous, however, is that a thread guide ring surrounding the dial cam is required, the carrier rods required for the suspension of said ring make the arrangement of further structural components, such as yarn stripers for example, largely impossible and both the thread guide ring and the carrier rods hinder free access to the dial cam. Up to now these disadvantages have had to be accepted since other known types of fastening for the thread guides (e.g. DE 29 34 694 A1, DE 39 20 408 A1) are either unusable in circular knitting machines of the type described initially or result in other serious disadvantages. These consist especially in the fact that the thread guides have to be adjusted individually and set again manually after a height adjustment of the dial arrangement and/or a relative rotation of the dial cam in relation to the cylinder cam, and this is complicated and time-consuming. Moreover, with these types of fastenings for the thread guides, no automatic adjustments of the dial cam and/or of the entire dial arrangement can be carried out with the aid of stepping motors or the like, and therefore no complex circular knitting machines can be realised in which these adjustments can be carried out when knitting is in progress.